Pyrolysis of physic nut residues was conducted under isothermal and dynamic
heating conditions in a vertical fixed bed type reactor at final temperature of 500,
700 and 900°C under N2. The solid, liquid, and gas products were in the ranges
of 26.94-29.04, 9.43-21.36, 51.70-61.54 wt% for slow pyrolysis, while those
attained from rapid condition were 11.16-15.25, 15.00-23.43, and 61.32-
73.84 wt%, respectively. Results indicated that char decreased with increasing
temperature and hold time. Char with highest fixed carbon of 85.32% with
relatively low volatiles of 9.28% was obtained by pyrolysis at 900°C for 60 min.
Release of volatile matter led to development of char porous structure. The
maximum liquid product of 21.35% was observed at the pyrolysis temperature of
900°C for 60 min under dynamic heating and 61.54% under isothermal heating
at 500°C. Decreasing hold time to 15 min caused 2 times decrease of liquid
yields. The liquid product mainly consisted of several fatty acids such as oleic
acid, palmitic acid and lignoleic acid in the range of 15-19%, 40-45%, and 25-
34%, respectively. Increase in temperature and hold time lead to greater
production of hydrogen, carbon monoxide, and light hydrocarbons. Mode of
heating displayed significant effect to the product distribution, LHV and H2/CO
ratio. Higher LHV values were obtained at 900°C under rapid pyrolysis
condition. Mole ratio of H2/CO close to unity was found in the case of pyrolysis
at 900°C for both slow and rapid trials. The LHV obtained from slow processes
were 7.8-15.0 MJ/Nm3 while those from rapid runs were 14.8-17.2 MJ/Nm3.
Keywords: pyrolysis, physic nut residue, fixed bed.